title: Mechanical processing of hyperviscous semen specimens can negatively affect sperm DNA fragmentation.
abstract: BACKGROUND
  The present study compared the DNA fragmentation in human sperm samples with reduced, physiological, and increased viscosity in order to evaluate whether the process used to reduce viscosity (expulsion of semen through a needle and syringe) alters significantly sperm DNA fragmentation.
  
  
  METHODS
  The seminal parameters of semen samples from 123 patients were evaluated and classified according to their viscosity. Samples with increased viscosity were submitted to a process of expulsion of semen through a 10-mL syringe and an 18-gauge (18G) needle to reduce the seminal viscosity. The DNA fragmentation of all samples was analysed using TUNEL assay (Terminal deoxynucleotidyl transferase mediated dUTP Nick-end labelling assay); in samples with increased viscosity, the fragmentation was assessed before and after the process of expulsion with syringe and needle.
  
  
  RESULTS
  There was no difference in DNA fragmentation between groups with different viscosity (P = 0.857). A significantly increase in sperm DNA fragmentation after expulsion of hyperviscous semen through the syringe was observed (P = 0.035).
  
  
  CONCLUSIONS
  There was no difference in DNA fragmentation rate between samples with reduced, increased and physiological viscosities; however, the physical process of expulsion of semen through a syringe and needle increased sperm DNA fragmentation.
authors.affiliation: Programa de Pós-Graduação em Medicina, Ciências Médicas, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Ana Paula S
authors.initials: AP
authors.lastname: Kussler
authors.forename: Anita M
authors.initials: AM
authors.lastname: Pimentel
authors.forename: Diego D
authors.initials: DD
authors.lastname: Alcoba
authors.forename: Isabella P
authors.initials: IP
authors.lastname: Liu
authors.forename: Ilma Simoni
authors.initials: IS
authors.lastname: Brum
authors.forename: Edison
authors.initials: E
authors.lastname: Capp
authors.forename: Helena V E
authors.initials: HV
authors.lastname: Corleta
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D053938:DNA Fragmentation; D006801:Humans; D020287:In Situ Nick-End Labeling; D008297:Male; D055595:Mechanical Phenomena; D011446:Prospective Studies; D012661:Semen; D013048:Specimen Handling / Q000009:adverse effects*; D013094:Spermatozoa / Q000502:physiology; D014783:Viscosity